Air mattress system with inflatable limb chamber

ABSTRACT

A system and method for controlling the flow of fluid for an inflatable mattress having multiple, non-interconnected inflatable chambers and a moveable inflatable limb elevation chamber. Each inflatable chamber can be selectively inflated and deflated to vary the pressure exerted from the mattress surface to selected areas of a human body, thereby preventing the formation of decubitus ulcers. The limb elevation chamber may also be selectively inflated and deflated as well being positioned at any desired portion of the inflatable mattress in order to raise one or more human limbs off the surface of the mattress.

BACKGROUND OF THE INVENTION

1. The Field of the Invention

The present invention relates generally to inflatable mattress systemsand, more specifically, to an inflatable mattress system having a limbelevation chamber for positioning on a mattress having multiple, fluidlyunconnected chambers that are selectively inflatable and deflatable.

2. The Relevant Technology

There is a belief that pressure sores or bedsore may develop when abed-ridden person does not move for extended periods of time. That is,immobile people (e.g., unconscious, comatose, paralyzed, or in a someother form of vegetative state) typically do not move or are unable tomove for extended periods of time (e.g., days, weeks). Immobile peoplewho are bed ridden may remain essentially in the same location on thebed fostering the development of bedsores.

Bedsores are visually disfiguring, are generally regarded as painful,and are typically debilitating. In some cases they are believed to leadto other maladies or medical complications, including bone and bloodinfections and infectious arthritis. Bedsores can lead to thedevelopment of penetrating holes below the sore that burrow into bone.Bedsores are believed to lead to scar carcinoma, a form of cancer thatdevelops in scar tissue. To reduce the incidence of bedsores in, forexample, rest homes, attending staff are typically charged with the taskof moving immobile people. That is, the immobile people are rolled ontheir beds from time to time for the purpose of a varying or changingthe parts of the body of the immobile persons that are in contact withthe support surface to reduce the risk of developing bedsores.Typically, moving immobile people is difficult because the immobileperson is not able to assist. In turn, it is believed that the attendingstaff from time to time suffer injury (e.g., pulled muscles, hernia)associated with the task of moving the immobile people. Bedsores are arisk for people/patients in hospitals, nursing homes, and even in theirown home when involved with a home health care treatment protocol underhome care.

It is presently understood that bedsores generally form at points ofpressure, where the weight of the patient's body presses the skinagainst the firm surface of the bed. The skin's blood supply is believedto be interrupted or reduced by the pressure in turn causing injury toskin cells. Unless the pressure is periodically relieved to allow fullblood flow to the pressed areas of the skin, the skin cells in the areamay develop ulcerations. The ulcerations can grow into notable bedsoressome in excess of the area of a quarter or half dollar.

Inflatable mattresses have been proposed for use by or with immobilepeople. Many in the past are believed to be difficult to operate,expensive, and unreliable. An inflatable mattress that varies thepressure in separate cells under different parts of the body and thataccurately and promptly operates to maintain the pressure and then varyit in accordance with individual or preprogrammed instructions isdisclosed in U.S. Pat. No. 7,219,380 B2 (Beck). However, it is believedthat use of the inflatable bed disclosed by Beck does not fully resolvethe incidence of bedsores in the limbs including particularly the legs.

To reduce the incidence of bedsores, various limb elevation products(like pillows) have been used to reduce the incidence of bedsores.However, nothing in the art is known to cause the limbs—e.g., ankles,arms and lower legs—to be periodically raised and lowered relative tothe surface of a support surface including the surface of an inflatablemattress.

BRIEF SUMMARY OF THE INVENTION

An inflatable mattress system includes a plurality of inflatablechambers assembled to define a support surface to support an occupanthaving at least one limb (e.g., arm or leg). Each of the inflatablechambers has at least one wall member forming an interior volume. It mayalso have multiple wall members. That is, each inflatable chamber may bein the shape of a cube or parallelepiped and in turn will have 6 sides.It may share a common side or wall with its adjacent inflatable chamber.Each wall member is made from a flexible material (e.g., plastic)selected to retain fluid. Each of the plurality of inflatable chambershas a chamber connector for fluid communication with the interior of thechamber. At least one wall member of each inflatable chamber isdeflectable between a first inflated position and a second inflatedposition different from said first inflated position. That is, eachchamber may be inflated to a selected level of inflation. Upon placementof a user or immobile person to the mattress, at least some of thechambers will deflect from the first inflated position to a secondinflated position.

A plurality of deflectable resistors are attached to each of theinflatable chambers and preferably to a deflectable wall member of eachchamber. Each of the deflectable resistors predictably varies itselectrical resistance upon deflection from a first configuration to asecond configuration. Each of the plurality of deflectable resistorsdeflects between its first configuration and its second configurationupon movement of said its wall member between its first inflatedposition and its second inflated position to generate a deflectionsignal upon application of electrical power to said deflectableresistors. The deflection of the resistors is thus reflective of saidinflatable chamber movement.

The inflatable mattress system preferably includes an inflatable limbelevation chamber configured for positioning on said support surface tosupport a limb of the occupant or user such as an immobile person. Theinflatable limb elevation chamber includes at least one elevationchamber wall member defining an elevation chamber interior volume. Theelevation chamber wall member is made from a suitable flexible materialselected to retain fluid. The elevation chamber wall member isdeflectable between a first inflated elevation chamber position and asecond inflated elevation chamber position different from the firstinflated elevation chamber position. In effect, the occupant's limb orlimbs are positioned on the limb elevation chamber causing the wallmember to move or to depress. The elevation chamber has an elevationchamber connector positioned through the elevation chamber wall memberfor fluid communication between a source of fluid and the elevationchamber interior volume.

A fluid source is provided for supplying a fluid under pressure intoeach interior volume of the plurality of inflatable chambers and intosaid elevation chamber interior volume. The fluid source may be a sourceof compressed air that is readily available or a suitable pump orcompressor provided to supply the compressed air. A first conduit meansis connected to each of the chamber connectors and to elevation chamberconnector for communicating fluid to and from the interior volume andthe elevation chamber interior volume. A second conduit means isconnected to a fluid source for communicating fluid to and from saidfluid source.

The inflatable mattress system all has a discharge means forcommunicating fluid away from the interior volume of each inflatablechamber and the elevation chamber interior volume. A valve is connectedto the first conduit means, the second conduit means and the dischargemeans. The valve is operable between a first position in which the valveplaces the first conduit means in communication with the second conduitmeans for supplying fluid from the fluid source to the interior volumeof the inflatable chambers and the elevation chamber interior volume anda second position in which the valve places the first conduit means influid communication with the discharge means.

The inflatable mattress system also includes a controller connected toeach of the plurality of deflectable resistors for supplying anelectrical signal thereto and for receiving a deflection signaltherefrom. The controller is preferably a microprocessor or equivalentand is configured to generate operating commands for operating the valvebetween its first position and its second position. The controller isconnected to the valve which is of the type that it is electricallycontrollable (e.g., motor driven, solenoid) to supply said operatingcommands to the valve to cause it to move between its positions.

In preferred or alternate configurations, the limb elevation chamber isremovable from the support surface. The controller includes a processorhaving a set of instructions for receiving the deflection signals andderiving an amount of desired inflatable chamber movement and forcalculating the desired fluid pressure for specific inflatable chambersand then generating a signal for placing the valve in its first positionand its second position.

In alternate configurations, the inflatable limb elevation chamber mayhave a plurality of chambers each separate from the other. Each chamberhas a deflectable resistor attached to its respective elevation chamberwall member to operate as the other deflectable resistors.

The inflatable limb elevation chamber may be in multiple geometricshapes but is preferably in the shape of half a cylinder. The limbelevation chamber also preferably has means for attaching or forsecuring said elevation chamber to said support surface and moreparticularly the mattress. The securing means is desirably a hook andpile fastener arrangement. Alternately, the limb elevation chamber mayextend substantially the width of the support surface with strapsextending from opposite ends which may be sized to extend under thesupport surface to be held by the weight of the occupant on the supportsurface.

BRIEF DESCRIPTION OF THE DRAWINGS

To further clarify the above and other advantages and features of thepresent invention, a more particular description of the invention willbe rendered by reference to specific embodiments thereof which areillustrated in the appended drawings. It is appreciated that thesedrawings depict only presently preferred embodiments of the inventionand are therefore not to be considered limiting of the scope of theclaims presented herein. The invention will be described and explainedwith additional specificity and detail through the use of theaccompanying drawings in which:

FIG. 1 depicts in perspective a hospital bed having an inflatablemattress system positioned thereon with an inflatable limb chamber ofthe present invention;

FIG. 2 is an exploded perspective view with a cut away surface of oneform of inflatable mattress of the invention;

FIG. 2A is a partial side view of an alternate arrangement of inflatablechambers useful in an inflatable mattress system of the presentinvention;

FIG. 3A shows in perspective an alternate arrangement of an inflatablemattress of the invention using several different sized inflatablechambers;

FIG. 3B is a perspective view of a limb elevation chamber of the presentinvention;

FIG. 4 is a front view of an alternate limb inflatable chamber of aninflatable mattress of the invention;

FIG. 5 illustrates a bottom view of the limb inflatable chamber of FIG.4;

FIG. 6 is a top view of the limb inflatable chamber of FIG. 4;

FIGS. 7A and 7B are block diagrams illustrating the electrical andmechanical elements of the inflatable mattress system and limb elevationchamber of the present invention; and

FIG. 8 is an exploded perspective view of an alternate form of amattress for use in the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Reference will now be made in detail to the preferred embodiments toillustrate and describe the features of the present inventions. Thevarious exemplary embodiments have an air mattress system 11 which canbe used with a conventional spring mattress, a separate base or supportor positioned on a frame of a medical bed. The system 11 includes amattress of the type having multiple, separate or isolated chambers thatcan be selectively inflated and deflated to increase and decrease thepressure exerted from various points of the mattress surface on a humanbody 10 having a torso 10A and lower extremities 10B and 10C whenpositioned on the mattress. A separate inflatable chamber 25 is nowprovided. It is inflated and deflated to raise and lower the limbs orextremities 10B and 10C of a person 10 on the mattress 20.

Referring to FIG. 1, an inflatable mattress system 11 includes ahospital bed 12 having a typical hospital bed frame 15 with aninflatable mattress 20 positioned on and supported by the bed frame 15.The inflatable mattress system 11 includes the inflatable mattress 20plus related components for inflating and deflating the mattress 20 suchas a separate chassis 19 that includes suitable controls 14 to operatethe inflatable mattress 20 plus a source 13 of air under pressure (e.g.,a compressor or an available hospital source) and suitable valves notillustrated to effect inflation and deflation of the chambers in themattress 20 (as discussed hereinafter) and a separate limb elevationchamber 25 through suitable tube bundle 17 as desired.

It should be noted that the air has been stated to be the material orfluid used to inflate the chambers 50A-E (FIG. 2) of the inflatablemattress 20 as well as the limb elevation chamber 25. Of course othersuitable fluids can be used including nitrogen gas or any other suitableand available gas. Inert gases such as argon may also be used. Variousliquids may also be used, but are less desirable because a leak can bemore difficult to deal with than the leak of a gas and in particular aharmless gas. Room air or compressed air is presently preferred as thedesired fluid because it is available and inexpensive. Compressed andfiltered air and nitrogen is sometimes available in a hospital setting.If the air or other gas is not dehydrated, the chassis may include oneor more dehydrating devices for any gas that may be used including air.A drying tower with desiccant is presently contemplated to dry the air.

In the embodiment of FIG. 1, the inflatable mattress 20 is shownpositioned on the hospital bed frame 15. Of course, those skilled in theart will recognize the inflatable mattress 20 may be positioned on orused with any suitable support structure including conventional bedframes, inner spring arrangements or structures, and various coil orleaf spring structures. Indeed, it may be positioned on a flat board orotherwise positioned on any structure of sufficient strength to supportthe inflatable mattress 20 with a user 10 positioned thereon with asuitable safety margin to accommodate visitors who may sit on the bed12.

In FIG. 1, the hospital bed frame 15 is shown to include anundercarriage 16A, a foot board 16B, and various hand rails 18A, 18B,18C and 18D. The hand rails 18A-D are all typically operable or movablebetween a stored position such as shown for hand rail 18C and a raisedposition such as seen for hand rails 18A, 18B and 18D. In the raisedposition, the handrails 18A, 18B, 18C and 18D function to retain aperson on the mattress 20. The hospital bed 12, and more specificallythe inflatable mattress 20 as here shown, is configured with an upperportion 20A, a middle portion 20B, and a lower portion 20C. The hospitalbed 12 has means (e.g., an electric motor connected to a suitablegearing arrangements) positioned in a housing 16C which is operable toraise and lower at least the upper portion 20A relative to the lowerportion 20C so that an occupant 10 can achieve different orientations ofthe occupant's body. For example, FIG. 1 shows the upper portion 20Apositioned at an angle 22 relative to the flat axis 21 which isessentially or effectively horizontal to show that the upper portion 20Acan be raised to elevate or raise the occupant's torso 10A above theflat axis 21 and in turn above the lower extremities 10B and 10C of theoccupant 10 oriented over the lower portion 20C.

The lower portion 20C typically has means associated with it so that italso may be elevated relative to the flat axis or horizontal 21 in amanner similar to the upper portion 20A. However, it may also be rigid.No matter how the lower portion 20C is oriented, the lower extremities10B and 10C would remain in contact with the support surface 20D foroccupants who are incapable of moving their extremities therebyincreasing the risk of bedsores if required to remain in or on the bed12 for extended periods of time.

In FIG. 1, a separate limb chamber 25 is positioned on the supportsurface 20D by any suitable means. It may be simply positioned bysomeone under the limbs 10B and 10C of an occupant 10. An alternatechamber 25A is shown positioned proximate the ankles to elevate thelower limbs 10B and 10C a suitable distance 23 (e.g., about 2 to about 4inches) so they are spaced away from the support surface 20D. In turn,air can pass under and about the extremities 10B and 10C to reduce therisk of bedsores. The limb chamber 25 or 25A also may be removably orfixedly attached to the support surface 20D by any means desiredincluding, various configurations of snaps, Velcro® hook and pilefasteners, glue or even by plastic welding. While the limb chamber 25may be attached to the support surface 20D, typical bed sheets may notcomfortably fit over it. Thus in some applications it will be preferredto have the limb chamber 25 or 25A unattached so that attendingpersonnel can position the inflatable support 25 on top of the typicalsheet (or similar bed covering) placed over and/or on the supportsurface 20D in a desired location. When not attached, the limb chamber25 and chamber 25A may have a tube 28 and 28A respectively connected fortransmitting or communicating air or fluid in and out for inflation anddeflation. The tubes 28 and 28A are preferably run under the inflatablemattress 20 for incorporation into the bundle of tubes 17 extending fromthe mattress 20 to the chassis 19. If the limb chamber 25 is attached tothe support surface 20D, the tube 28 may extend through the mattress 20or be secured tightly to the exterior of the mattress 20 (not shown).

The inflatable chamber 25 is here shown to have a width 26 which isshown to be less than the width 27 of the support surface 20D. The width26 is any width suitable to extend under both limbs 10B and 10C of anoccupant 10 or user when the limbs 10B and 10C are positioned generallyin alignment as shown in FIG. 1. It is contemplated that in preferredembodiments, the width 26 will be at least half the width 27 of thesupport surface 20D and preferably about two thirds to three fourths thewidth 27 of the support surface 20D. The inflatable chamber 25 may evenextend the full width 27 of the support surface 20D.

Referring now to FIG. 2, the inflatable mattress 20 is illustratedhaving a chamber portion 50 that fits into and is positioned within ahousing portion 40. FIG. 2 also illustrates a bottom or support 30 thatfunctions much like an inner spring for use in bed arrangements in whichthe mattress system is separately supported and not moveable as themattress system 11 in FIG. 1.

Chamber portion 50 seen in FIG. 2 is a matrix of inflatable chamberssuch as representative chambers 50A-E. The size and shape of selectedchambers can vary. For example fewer chambers are needed in the upperportion 20A of a bed like bed 20. As stated, the chamber portion 50 ispositioned within a separate housing portion or base 40 that may bepositioned. The base 40 may be positioned on top of the bottom orsupport 30 or on top of the frame 15 and more specifically the housing16C.

As constructed, the mattress 20 is a parallelepiped which is alsogenerally rectangular in projection and sized in height 40H, in length40I and in width 27 to fit on or in a suitable bed support like support30 or on a bed frame like the housing 16C (FIG. 1). Thus, a mattress maybe sized to fit into or on other conventional bed frames. Double, queensize and king size versions are contemplated. The mattress for largerversions may have one base 40 sized to accommodate two separate sets ofchambers 50 in a side by side relationship.

The container or base 40 of the mattress 20 of FIGS. 1 and 2 has anupper surface 40B that may be, and in this embodiment is, the same asthe surface of the mattress 20D. The base 40 also has a bottom surface40E and sides 40F, 40G, 40J and 40K. The bottom surface 40E and sides40F, 40G, 40J and 40K are each made of a material that selected to beflexible and have suitable wearing characteristics to resist punctures,is cleanable, and relatively strong. A wide variety of syntheticproducts including plastic (e.g., polypropylene) or plastic-likematerials may be used to fabricate the base 40. In some cases, themattress 20 may have padding for comfort and insulation as discussedmore fully hereinafter.

In FIG. 2, the base 40 is shown having a lid 45 which is discussed morefully below. The bottom surface 40E and the sides 40F and 40G may bemade of a thicker or more durable material in relation to the uppersurface so the mattress is able to maintain a reasonable degree ofrigidity when inflated. However, the upper and lower surfaces 40D and40E as well as the sides 40F and 40G may be made of the same material.

As seen in FIG. 2, the bottom or support 30 depicted is a generallyrectangular structure having opposite side walls 31 and 32 and oppositeends 33 and 34. It is here shown to have four separate compartments 46,47, 48 and 49 separated by compartment dividers 35, 36, 37 which extendbetween the lower surface 39A and the upper surface 39B to providestructural support to the side walls 31 and 32 as well as support forthe upper surface 39B (shown in cut-away). The bottom or support 30functions to support the base 40 with the chambers 50 in the base and auser 10 positioned thereon. The surface 39B and preferably the bottomsurface 39A extends between the sides 31 and 31 and the ends 33 and 34.The number of compartments 46-49 in the bottom or support 30 may vary.The compartments 46-49 may be filled with any suitable material toprovide the rigid support desired. Latex, coil springs, leaf springs,spring lattice structures and even liquid or air chambers may be used toprovide the desired rigidity and support.

In some embodiments, the cover 45 may function as the upper surface 40B.It would then be configured to be securely fastened to the side walls40F, 40G, 40J and 40K and more specifically to the upper rim 41 of theside walls. 40F, 40G, 40J and 40K by any suitable means such as azipper. For example, the adjoining edges may be formed with a zipperlike arrangement much like that found on Zip-Lock® bags. If one edgelike edge 43 remains zipped, the edge then function much like a hinge sothe cover or lid 45 may be removed. Of course the cover 45 is not rigidas shown with a plastic like material of construction. The chamber has asuitable aperture like aperture 40A to allow tubes from each chambersuch as chambers 50A-E to be assembled into a tube bundle 17 to passthrough aperture 40A in the bottom 40E for further connection to thechassis 19 of the controller 14 for supplying and removing fluid (e.g.,air) for the purpose of inflation and deflation.

In other configurations, the lid 45 may be made from a fabric such asLycra®. If the side wall 43 of chamber 40 is formed with a rib along anedge 43A, conventional sewing stitches may be used to secure removablelid 45 to the rib at the edge 43A. Removable lid 45 is then secured toside walls upper edge 41 with suitable fasteners that can includebuttons, snaps, interactive hook and pile fasteners (e.g., Velcro®fasteners) as well as other forms of zippers. Virtually any suitablemechanism to associate the cover 45 to the chamber 40 may be used toeffect a mechanical association.

While the chambers 50 shown in FIG. 2 are shaped essentially like abrick, they may be in any suitable configuration or shape desired. Forexample, the chambers maybe cube like or even cylindrical in shape.Optional and solid (e.g., neoprene) material 50A may be used to spaceselected chambers 50B and 50C in any suitable or desired pattern. Asshown in FIG. 2A, the chambers in one or more or all of the sections20A, 20B and 20C may be formed in a thin wafer like form. That is one ormore chambers like chambers 50D and 50E may be stacked one on top of theother. Alternately, a non inflatable portion 50G may be positionedbetween inflatable chambers 50F and 50H. In other words, the chambersmay be assembled in a large number of configurations to meet any desiredsupport configuration.

In the illustrated embodiment, the mattress system 11 is sized ordepicted as an approximate single or twin mattress for use in a typicalhospital bed. However, any mattress size (e.g. king, queen, or full) maybe manufactured using the inflatable multi-cell design described hereinwithout departing from the intended scope and spirit of the invention.

The hospital bed mattress 20 of FIGS. 1 and 2 functionally may be viewedas having the three portions or sections 20A, 20B and 20C ashereinbefore noted. In use, the gluteus maximus of the user would bepositioned in and supported by the middle portion 20B. The back of theuser would be supported by the upper portion 20A, and the user's lowerextremities 10B and 10C (e.g., legs, thighs and feet) would be supportedby the lower portion 20C.

In use, it is possible that one or more chambers of the matrix 50, suchas chambers 50 A-E may be damaged and start to leak. In that event, itis desirable that coverings be removable, such as cover 45, so that onemay access a chamber and be able to effect a repairs (e.g., affix asuitable patch). Thus, any of the plurality of inflatable chambers 50within inflatable mattress system 20 may be easily replaced or repaired.

Referring now to FIG. 3A, an alternate chamber arrangement 100comparable to chambers 50 is depicted. The chamber arrangement 100 issized to fit within a base like base 40; and it has multiple cells orinflatable chambers of differing sizes arranged in an advantageousmanner to minimize the occurrence of bedsores in a patient.Specifically, the chamber arrangement 100 includes a group of elongatedinflatable chambers 120, 121, 122 positioned to support the head of anoccupant 10 when the occupant is positioned normally on the chamberarrangement 100. The elongated inflatable chambers 120, 121, 122 areeach rectangular in shape and sized to extend the width 123 of thechamber arrangement 100. In alternate configurations, the chambers 120,121 and 122 may extend a distance 124A and 124B from the centerline 124Dof the mattress selected to provide suitable support for the head withan associated portion 124C not typically associated with supporting apatient made of a suitable flexible material like neoprene.

The chamber arrangement 100 of FIG. 3A also has a plurality of largeinflatable chambers here shown to be chambers 111, 112 and 113. They arelocated so that when an occupant is positioned on the chamberarrangement 100, the occupant's shoulders are positioned to be supportedby chambers 111, 112 and 113. A larger chamber is shown because moresupport is typically desired for the user from the neck area down towardthe middle of the back. At the same time, this area is not typicallyprone to the incidence of bedsores.

In FIG. 3A, the middle of the chamber arrangement 100 is shown withlarge brick-like chambers 106, 107, 108 and 109 surrounding a matrix of9 cube-like interior chambers 125-133. The matrix of chambers 125-133 ispositioned to support the small of the back and the gluteus maximus ofthe occupant like occupant or patient 10 when positioned normally on thechamber arrangement 100 with his or her head proximate chambers 120-122.The risk of bedsores by an essentially chronically immobile occupantover a longer period of time is typically higher in this region. In turnthe support can be varied by inflating and deflating selected chambersof the matrix of chambers 125-133 to vary the supporting locations toavoid the creation of bedsores at various supported locations. Thelarger outer chambers 106-109 do not typically provide support to torsoof the occupant. Rather they will typically be supporting the arms andhands which weigh less and which have less skin or surface in contactwith the chamber arrangement 100 and thus do not typically experiencebedsores.

The chamber arrangement 100 of FIG. 3A next has a series of largerchambers 134, 135 and 136 which will be proximate the thighs of achronically immobile user positioned normally on the chamber arrangement100. The skeletal configuration of the thighs keeps them suspended. Thatis the weight of the thighs are borne more by the hips and the kneesthan by the mattress. Thus the incidence of bedsores is typicallyminimal in the region of the thighs.

The lower portion of the chamber arrangement 100 in FIG. 3A has a matrixof smaller chambers 137-142 positioned to support the feet and someportion of the lower leg or calf area. These chambers 137-142 areinflated and deflated in different patterns or configurations to varythe support to the feet and lower calves to reduce the incidence ofbedsores. Inasmuch as the feet are typically positioned close to thecenterline 124D of the bed, the outer chambers 104 and 105 are largerand may be about twice the size of the a chambers 137-142 of the matrix.

Selective inflation and deflation of the illustrated small inflatablechambers provides a variation of the pressure at points of contactbetween the mattress surface and the body (skin) at the most commonplaces for the development of bedsores on a bed-ridden individual. It isbelieved that the change in location may impact on blood flow to theskin and also allow ventilation. The system operates so that thepressure in the small chambers varies from, for example, about 1.0 to1.1 pounds per square inch (psi). While representing less than a 10%change in pressure, the result structurally is notable. The other largerchambers 104-109, 134-136 and 111-113 are located adjacent the group ofsmall inflatable chambers but typically are not supporting the body of achronically immobile person.

In a preferred embodiment, the inflatable chambers are sized and placedaccording to the average weight and size of a typical human body. Inother configurations, inflatable chambers may be larger sized toaccommodate the weight of a very large person or smaller sized toaccommodate the weight of a baby or child. Preferably, elongatedinflatable chambers 120, 121, 122 are sized in a range of approximately36.0 inches by 3.7 inches to 37 inches by 4.7 inches, and are preferably36.5 inches by 4.2 inches. Large inflatable chambers, 111, 112, 113 aresized in a range of approximately 13.0 inches by 11.3 inches to 14.0inches by 12.3 inches, and are preferably 12.5 inches by 12.8 inches.Small inflatable chambers 137-142 are sized in a range of approximately8.3 inches by 6.4 inches to 9.3 inches by 7.4 inches, and are preferably8.8 inches by 6.9 inches. Inflatable chambers 125-133 are sized in arange of approximately 13.0 inches by 6.4 inches to 14.0 inches by 7.4inches, and are preferably 12.5 inches by 6.9 inches. Preferably,elongated inflatable chambers, large inflatable chambers, smallinflatable chambers and medium inflatable chambers are approximately 3.0inches in height 143.

The inflatable chambers illustrated in FIG. 3A are not fluidlyconnected, so each inflatable chamber may be individually inflated anddeflated. In some configurations, each chamber is separate and removablefrom the others. In such an arrangement the individual chambers areeasily removable; and thus one may replace an inoperative or defectivechamber.

It has been found that in some instances, bedsores are more easilygenerated on the heels of a user as well as along the back of thecalves. To help reduce the incidence of bedsores a separate chamberpositioned to elevate the feet and calves of the chronically immobileoccupant has been found useful.

FIG. 3B illustrates one embodiment of a limb elevation chamber 25 usefulto elevate the feet and calves of a chronically immobile occupant.Elevation chamber 25 has a top surface 26, a bottom surface 27, a rightsupport strap 28 and a left support strap 29. In the illustratedembodiment, elevation chamber 25 is shown as substantially rectangularin projection with an accurate top surface 26. It in effect looks likehalf of a cylinder. However, elevation chambers 25 of varying shapessuch as circular, spherical, cylindrical, toroidal, ovular, triangular,and other shape that is desired so long as it may be positioned toelevate the feet and calves of the chronically immobile occupant. It isalso contemplated that a limb elevation chamber 25 can be formed to havemultiple separately inflatable and deflatable compartments 26A, 26B and26C. Each compartment 26A, 26B and 26C will have its own separateconnector such as connector 31A (as hereinafter described) to receiveand supply fluid for selective inflation and deflation.

In one embodiment, bottom surface 27 is approximately 12 inches wide 27Aand 35 inches long 27B. The curved or semicircular top surface 26 has aheight of about 3 to 5 inches and preferably about 4 inches high 26A.The height 26A is selected so that the chamber 25 will elevate the feetand calves or other limb of the chronically immobile occupantsufficiently to allow the blood flow to be normal and some air tocirculate to reduce the incidence of bedsores. The enumerated dimensionsare provided as illustrative, and should not be limiting, as otherdimensions may be used as desired.

In operation, the bottom surface 27 of the chamber 25 lies flat on thesurface of a mattress like mattress 20 with the straps 29A and 29Bextending over and along the sides (e.g., sides 33 and 34 in FIG. 1).The top surface 26 supports one or possibly several body parts of apatient. For example, an individual's ankles, calves or thighs may beplaced on top surface 26 so as to elevate the feet and lower legs orcalves and keep them from contact or substantial contact with theassociated mattress. In another embodiment, the chamber may bepositioned to elevate an individual's arm so as to elevate the hand,forearm and elbow from the surface of the mattress system 20.

Support straps 29A and 29B are sized to extend and run vertically alongthe edges of mattress 20 to secure elevation chamber 25 to the surfaceof a mattress like mattress 20. In one embodiment, straps 29A and 29Bare substantially as long as the depth of the mattress and are affixedto the sides of the mattress. For example, straps 29A and 29B areapproximately 5 inches long and 12 inches wide, although straps of otherlengths and widths are contemplated and fall within the scope of theinvention. In another embodiment, the inside walls 29E and 29F of straps29A and 29B are surfaced with one part 29G (see FIG. 1) of Velcro® hookand pile fasteners 29C and 29D positioned to interact with a suitablehook or pile portion affixed to the sheet or similar bed coveringwrapped about the mattress such as mattress 20. The part 29G is affixedto a sheet or similar bed covering to have a length 29H that allows theuser to secure the limb chamber 25 along the length or axis 21 of themattress 20. That is, the straps 29A and 29B with hook and pilefasteners function as a securing means for removably coupling the straps29A and 29B and in turn the chamber 25 to the mattress 20 of a systemlike system 11. In addition to Velcro® connectors, other securing meansmay be used to either fixedly attach or removably attach straps 29A and29B to the sides of mattress system 20. For example, straps 29A and 29Bmay be long enough to wrap around the underside of mattress system 20and attach to each other or be held in place by the weight of themattress 20. Alternately, the straps 29A and 29B may include a malleablemetal piece that can bend about the mattress or that can clamp or gripthe mattress. Alternately, the straps 29A and 29B can be secured using abutton arrangement, a snap arrangement, hooks or the like. It ispresently contemplated that a straps 29A and 29B are preferably made ofa suitable plastic or cloth with a length so they can be tucked underand between the mattress 20 and the support thereunder 16C (FIG. 1).

Elevation chamber 25 is constructed of any substantially non-porous,flexible material. For example, elevation chamber 25 may be manufacturedof a vinyl material, the thickness of the material falling within arange from about 0.015 inches to about 0.04 inches, and preferably, is0.02 inches. Any similar material may be used. A suitable materialshould be sealable to create an interior volume in the interior of theelevation chamber 25, such that a fluid may be introduced to inflate thecell. In one preferred embodiment, one surface of the inflatable chamberis constructed of the non-porous, flexible material. However, one ormore of the surfaces may be manufactured of the flexible material andthe remaining surfaces may be manufactured of a different material.

The top surface 26 is relatively smooth and adapted to support at leasta portion of the weight of an individual (e.g., weight of one or bothlegs) positioned on the surface of the elevation chamber 25. The bottomsurface 27 or the top surface 26 has a chamber connector 31A that eitherintroduces fluid into or releases fluid from the inflatable chamberlocated interior to elevation chamber 25. Chamber connector 31A ispositioned on any surface of elevation chamber 25 but is preferablylocated on the bottom surface 27 or on a sidewall 31B or 31C. It isconfigured to connect to a conduit means for communicating fluid to andfrom the interior volume 27A. In the illustrated embodiment, chamberconnector 31A is an aperture with a fitting formed in the bottom ofelevation chamber 25. However, chamber connector 31A may be any elementsuitable for fluidly communicating between the interior volume ofelevation chamber 25 and any element that supplies, releases or measuresfluid such as, for example, the chassis 19 of controller 14 (FIG. 1).Suitable barb connectors and bayonet connectors may also be used andpositioned in an suitable indentation formed in the bottom 27.

In one embodiment, a deflectable resistor 31D is secured to a surface ofelevation chamber 25 to detect the presence or absence of a pressurepoint, such as a patient's weight, on the chamber. In a preferredembodiment, deflectable resistor 31D is secured to the top surface 26.Details of deflectable sensor 31D are further described in U.S. Pat. No.5,583,476 (Langford). With a voltage applied to the deflectable sensor31D, the deflectable sensor 31D can supply a signal reflecting thedeflection of the surface 26 caused by the users limbs such as limbs 10Band 10C. The degree of deflection can reflect inflation as well as thelocation of the supported extremities. Elevation chamber 25 may not havea deflectable sensor secured to any surface, in which case elevationchamber 25 is simply inflated and deflated manually.

FIGS. 4, 5, and 6 illustrate, respectively, a front view, a bottom viewand a top view of an alternate inflatable chamber 140. Inflatablechamber 140 has a top surface 151 and a bottom surface 152. In theillustrated embodiment, inflatable chamber 140 is a half cylinder and issubstantially rectangular in projection. However, inflatable chambers ofvarying shapes such as circular, spherical, cylindrical, toroidal,ovular, triangular, and other shapes could be used as well for specificapplications.

Inflatable chamber 140 is constructed of any substantially non-porous,flexible material. For example, inflatable chamber 140 may bemanufactured of a vinyl material. The thickness of the vinyl material istypically within a range from about 0.015 inches to about 0.04 inches,and preferably, is about 0.02 inches. Any similar material may be usedso long as it is suitable for the formation of a fluid retainingchamber. Thus a fluid (e.g., air, nitrogen) may be introduced to inflatethe chamber 140 and is sealed so that the fluid does not escape. In onepreferred embodiment, the outer or upper surface 151 of the inflatablechamber 140 is constructed of the non-porous, flexible material.However, at least the bottom surface 152 of the inflatable chamber 140may be manufactured of the a different material that is not porous andrigid. The bottom surface 152 may be a solid in some applications.

The top surface 151 is relatively smooth and adapted to support at leasta portion of the weight of an individual positioned on the surface ofthe inflatable mattress system 120 of FIG. 3A. The bottom surface 152has a chamber connector 155 that either introduces fluid into orreleases fluid from the interior volume of inflatable chamber 140.Chamber connector 155 is positioned on any surface of inflatable chamber140 and is configured to connect to a conduit for communicating fluid toand from the interior volume of inflatable chamber 140. In theillustrated embodiment, chamber connector 155 is an aperture with a barbconnector 156 sealingly fitted into the aperture. The barb connector 156is sized to receive a conduit for connection to the a chassis likechassis 19. A separate hose clamp may be positioned over the conduitproximate the barb to effect a secure mechanical connection. The chamberconnector 155 is preferably positioned in a recess in the bottom surface152 so that the fluid chamber 140 may rest essentially flat on thesurface of the mattress like surface 20D. The chamber connector 155 maybe any other device or structure to connect with a conduit and suitablefor fluidly communicating between the interior volume of inflatablechamber 140 and any element that supplies, releases or measures fluidsuch as, for example, a valve, a connector, a PVC or metal conduit, afemale or male adapter or a liquid tight flexible conduit and fitting.

A deflectable sensor 150, such as a deflectable resistor, is secured toa surface of inflatable chamber 140 to detect the level of deflection ofthe surface 151 and in turn the degree of inflation of the chamber 140.It may also be used in some applications to sense the presence orabsence of a pressure point that may be caused by the presence of auser's extremities. In a preferred embodiment, deflectable resistor 150is secured to the top surface 151. Deflectable resistor 150 consists ofa substrate with an electrical conductor thereon that predictablychanges in electrical conductivity as it is bent. The change in theinflatable chamber 140 from a first configuration, i.e. a first inflatedposition, to a second configuration, i.e. a second inflated position,varies the resistance of the deflectable resistor 150 from a firstresistance to a second resistance in a predictable way. At any time, theresistance is measured by applying an electrical signal such as avoltage or a current to the deflectable resistor 150. An electricalconnection or connections is made to deflectable resistor 150 to capturethe deflection information so as to determine the amount of bending ormovement that occurs on top surface 151 between a first inflatedposition and a second inflated position of the inflation chamber 140,referred to herein as a deflection signal that is reflective of themovement of the inflation chamber 140.

A suitable deflectable resistor for purposes of detecting a pressurepoint on the surface of inflatable chamber 140 is a Bend Sensor®detector manufactured by Flex Point Sensor System, Inc. of Draper, SaltLake County, Utah. It is also described in U.S. Pat. Nos. 5,157,372 and5,583,476, the disclosures of which is hereby incorporated by referencefor all purposes. Deflectable resistor 150 is affixed to the surface ofinflatable chamber 140 by any suitable means such as glue. It ispreferably is affixed by a pressure sensitive adhesive that adheres totop surface 151 without affecting the integrity of the material used tomanufacture deflectable resistor 150.

Referring now to FIG. 7A, a block diagram illustrating the electricaland mechanical elements for controlling the operation of the inflatablemattress system of the present invention is shown. In the illustratedembodiment, a controller 200 comparable to controller 14 (FIG. 1) iscommunicatively coupled to a processor 205 which operate together toprovide for the selective introduction, discharge and measurement of afluid within the inflatable chambers 220, 225, 230 and an elevationchamber 280 based upon a deflection signal received from the deflectableresistors 235, 240, 245 and 285. Although three inflatable chambers 220,225, 230 and one elevation chamber 280 are illustrated and describedwith respect to FIG. 7A, any lesser or greater number of inflatablechambers and elevation chambers may be used depending upon theparticular needs of the desired inflatable mattress system.

In the particular device illustrated, controller 200 is comprised ofvalve controller 275, fluid controller 265 and reading device 270. Inalternate embodiments, controller 200 may be a mechanical or electricaldevice that incorporates the functions and operations of valvecontroller 275, fluid controller 265 and reading device 270 in either asingle device or multiple devices. Valve controller 275 controls theoperation of valve assembly 215 by sending a series of signals to thevalve assembly 215 to operate to supply fluid from source 212 to thechambers 220, 225, 230 and 280 one at a time or in a suitablecombination based on the particular chambers involved. In thisembodiment, the valve 215 performs various mechanical operations, suchas selecting one or more particular inflatable chambers for inflation,deflation or measurement. Fluid controller 265 controls the pressure andduration of the flow of fluid from fluid source 212 (comparable tosource 13, FIG. 1) to any one of the inflatable chambers 220, 225, 230and elevation chamber 280 by providing a signal to fluid source 212 toinitiate the introduction of fluid to inflate a selected inflatablechamber. Reading device 270 receives a deflection signal fromdeflectable resistors 235, 240, 245, 285 and operates to determine thelocation and amount of an individual's weight that is located oninflatable chambers 220, 225, 230 and elevation chamber 280.

In a preferred embodiment, controller 200 is provided with a processor205 that includes a programmable integrated circuit such as M30262manufactured by Renesas. However, any suitable programmable integratedcircuit may be used to supply operating commands that control theoperation of valve assembly 215 and fluid source 212, as well as receivedeflection measurements from the surface of inflatable chambers 220,225, 230 and elevation chamber 280, as well as pressure measurementsfrom within the respective interior volume of inflatable chambers 220,225, 230 and elevation chamber 280. For example, processor 205 mayinclude or be embodied in an application specific integrated circuit.

Controller 200 is also coupled to valve assembly 215 through a pressuresensor 255 for reading the pressure within inflatable chambers 220, 225,230 and elevation chamber 280. Pressure sensor 255 is typically apressure transducer capable of measuring the amount of pressure withinan inflatable chamber when such as request is issued by eithercontroller 200 or processor 205. However, any suitable pressuremeasuring device may be used. In operation, controller 200 is instructedto retrieve a pressure reading within a particular inflatable chamber,for example, inflatable chamber 220. Valve assembly 215, via informationfrom valve controller 275, selects inflatable chamber 220 for a reading.Once chamber 220 is chosen, the pressure reading is taken by pressuresensor 255 and relayed to processor 205 via controller 200.

Processor 205 preferably comprises any computer processor capable ofexecuting a series of instructions. It is configured to access data fromcontroller 200 and issue commands to controller 200. For example,processor 205 may contain instructions for selecting certain inflatablechambers for inflation or deflation based on deflection informationreceived from deflectable resistors 235, 240, 245, 285. Processor 205may also contain instructions for randomly selecting inflatable chambers220, 225, 230 and elevation chamber 280 for inflation and deflation in aparticular pattern that provides varying pressure points on the skin ofan individual's body, thereby preventing the formation of bedsores.

In the illustrated embodiment, fluid source 212 is a pump 210 whichsupplies fluid via a fluid passage or conduit to valve assembly 215through a check valve 260 and a three-way valve 250. Three-way valve 250allows fluid source 212 to introduce fluid into inflatable chambers 220,225, 230 and elevation chamber 280 through valve assembly 215. Inaddition, three-way valve 250 is coupled to the atmosphere through afluid discharge outlet such that fluid may be removed from inflatablechambers 220, 225, 230 and elevation chamber 280 through valve assembly215. Check valve 260 preferably has a crack pressure of 0.15 psi, whichprevents back flow through to the fluid source 212. Fluid source 212 apump 210 that draws air from the atmosphere and is sized to provide atleast ½ to 2 pounds per square inch of pressure in inflatable chambers220, 225, 230, and elevation chamber 280. The pump may be a 112 VACmodel # DDL15B-121, 23 L/m linear diaphragm pump manufactured by Gastthat outputs approximately 5 pounds per square inch of pressure.However, any suitable pump may be used that is sized in accordance withthe particular requirements of the inflatable mattress system.

Valve assembly 215 is fluidly coupled to inflatable chambers 220, 225,230 and elevation chamber 280. In operation and with reference to anoperating command received from controller 200, valve assembly 215selects a particular inflatable chamber (or a plurality of chambers) forinflation or deflation. In inflation mode, valve assembly 215 operatesto introduce fluid from fluid source 212 through pump 210 into aselected inflatable chamber. In deflation mode, valve assembly 215releases fluid into the atmosphere from a selected inflatable chamberusing three-way valve 250 as a fluid discharge outlet. Valve assembly215 may be any suitable element for selectively supplying fluid from afluid source 212 or communicating fluid away from a mattress system. Oneparticular embodiment of a valve assembly 215 is described in greaterdetail with reference to FIGS. 8-15.

FIG. 7B illustrates another embodiment of the electrical and mechanicalcontrols of an inflatable mattress system. In this embodiment, limbelevation chamber 290 does not have a deflector resistor securedthereto. Therefore, elevation chamber 290 is inflated and deflatedmanually. That is, the controller 200 is operated to cause the valve 215to supply inflation fluid to the elevation chamber 290 and to removeinflation fluid by venting it.

In another embodiment, controller 200 determines the presence of anelevation chamber 25, 280 by querying for an electrical signal from adeflector sensor 31, 285 communicatively coupled to an input on readingdevice 270 reserved for an elevation chamber 25, 280. If an electricalsignal is received by controller 200 from the deflector sensor 31, 285,controller 200 determines that an elevation chamber 25, 280 is present.The controller 205 communicates the presence, or lack thereof, of theelevation chamber 25, 280 to the processor 205, with the processor 205acting in accordance with its programming instructions.

For an inflatable chamber selection operation, controller 200establishes that a particular inflatable chamber is to be selected.Processor 205 may instruct controller 200 to select a particularchamber, or cell, or controller 200 may select a particular cell on itsown. Controller 200 issues an operating command or signal to valveassembly 215 to a select a particular inflatable chamber, for exampleinflatable chamber 230. First valve plate 300 rotates relative to secondvalve plate 305 until aperture 350 or aperture 355 aligns with theoutlet aperture 365 corresponding to inflatable chamber 230. Typically,an inflate operation, deflate operation and/or measurement operationfollows a selection operation.

For an inflatable chamber inflation operation, controller 200establishes that selected inflatable chamber 230 is to be filled withfluid. Processor 205 may instruct controller 200 to inflate the selectedcell or the instruction may come from controller 200. In the embodimentillustrated in FIG. 7A, fluid controller 265 of controller 200 sends anoperating command or signal to fluid source 212 instructing the sourceto supply fluid into inflatable chamber 230 at a particular strength fora particular duration. Controller 200 also sends an operating command tothree-way valve 250 that an inflate operation is about to occur. Inresponse to the signals, three-way valve 250 is placed into the inflateposition and fluid flows from fluid source 212 through check valve 260,three way valve 250 and into valve 215.

For an inflatable chamber deflation operation, controller 200establishes that fluid is to be removed from selected inflatablechamber, or cell, 230. As stated previously for an inflate operation,processor 205 may instruct controller 200 to deflate the selected cellor the instruction may come from controller 200. Controller 200 sends anoperating command or signal to three-way valve 250 that a deflateoperation is about to occur. In response to the operating command fromcontroller 200, three-way valve 250 is placed into the deflate position,thereby creating a fluid path from valve assembly 215 to the environmentto release the fluid.

Controller 200 also receives measurement information regarding thedeflection of deflectable resistors 235, 240, 245, 285 located onelevation chamber 280 and inflatable chambers, or cells, 220, 225, 230respectively. Reading device 270 located within controller 205 iscoupled to deflectable resistors 235, 240, 245, 285. At prescribedperiods of time, reading device 270 receives deflection signals fromdeflectable resistors 235, 240, 245, 285. For example, if anindividual's body is resting on elevation chamber 280 or inflatablechambers 220, 225, 230, the deflectable resistors 235, 240, 245, 285sense a certain amount of deflection on one or more of the inflatablechambers 220, 225, 230, and elevation chamber 280. In response, adeflection signal representative of the deflection is transmitted fromdeflectable resistors 235, 240, 245, 285 to the reading device 270 incontroller 200. Reading device 270 then transmits the deflection signalsto processor 205, which acts in accordance with its programminginstructions to prepare output information for display and to supplyoperation signals to inflate and deflate in accordance with apreselected desired configuration to support the user 10 on a mattresslike mattress 20.

Processor 205 uses the deflection information from deflectable resistors235, 240, 245, 280 in a variety of ways. For example, the deflectionsignals sent by the deflectable resistors 235, 240, 245, 280 providesprocessor 205 with information regarding the position of a human body onelevation chamber 280 and inflatable chambers 220, 225, 230. Processor205 may then instruct controller 205 to alter the pressure within theinterior volumes of elevation chamber 280 and/or inflatable chambers220, 225, 230 at prescribed intervals to vary the pressure exerted fromthe surface of the inflatable chambers 220, 225, 230 and elevationchamber 280 on the skin of the individual, thereby reducing theformation of bedsores.

A suitable configuration for valve 215 is fully described and disclosedin U.S. Pat. No. 7,219,380 B2 (Beck) the disclosure of which is herebyincorporated by this reference.

FIG. 8 is an illustration depicting an alternate configuration of amattress 400. A base 402 is formed with two opposite ends 404 and 406and two opposite sides 408 and 410. Although the base is shown as arigid structure, it is preferably made of a suitable material such asvinyl or any other material that is easy to keep clean, and is thickenough to protect the in inflatable chamber member 416 from, forexample, accidental punctures, wear and tear. The material is also waterresistant to keep fluids from entering and creating mold. The oppositeends 404 and 406 and the sides 408 and 410 of the base 402 define avolume 412 sized to receive therein a bottom foam insert 414 and aninflatable chamber member 416. A cover 418 is shown separate from azipper member 420. However, the edge 422 of the cover 418 in use is sewnto and along the upper edge 424 of the zipper member 420. The lower edge426 of the zipper member is sewn to or attached by any suitable means tothe edge 428. The zipper 430 of the zipper member 420 extends around theperimeter of the zipper member 420 so that the cover 422 may be removedto access the inflatable chamber member 416 and the bottom foam insert414. A separate foam insert (not shown) may be placed between the cover418 and inflatable chamber member 416. The top 418 is here shown as aplanar or smooth surface typically made of a synthetic material from afamily of available plastics but preferably a biaxial stretchablematerial like Lycra®. A biaxial stretchable material is preferredbecause it will deform in both transversely and lengthwise when a useris positioned thereon thereby minimizing the deformation of otherchambers and in turn false readings suggesting deflection of otherchambers. The material for the top 418 is also one that is susceptibleto cleaning with a damp or wet cloth and one that can withstand strongcleaning agents of the type used in a typical hospital or medical carefacility. The top 418 may be made in other physical configurations asdesired including a “pillow top” variety.

At one end of the illustrated mattress 400 in FIG. 8, the end chamber432 is sized to be about half the height 434 of the inflatable chambermember 414. In the space 436 under the end chamber 432, a controlstructure 438 is positioned. The sides 406, 408 and 410 may be adjustedso that the side 406 extends upward toward the end chamber 432 andreward along the bottom 433 of the end chamber to form a notch toreceive the control structure 438. That is, the control structure 438 ispreferably positioned outside the base 402 so that head from thecomponents in the control structure 438 is not retained within thecontrol structure 438 itself and also the enclosure formed by the base402 and the top 418 when zipped together. The control structure 438 isshown in exploded view with an enclosure or housing 440 sized to receivea valve structure 442 with a microprocessor board 444 assembled with aplurality of assembly screws 446. The valve structure 442 is connectedto a source of air or other fluid (not shown) and configured to directthe air or other fluid to the separate chambers like chamber 432 in theinflatable chamber member 416 via suitable conduits like conduit 448that extend to selected the chambers in the inflatable chamber member416 through suitable apertures (not shown) in the wall 406 of the base402. A hand operator 450 is shown with optional controls 452 (e.g.,touch pad) connected by a suitable conductor 454 to the microprocessor444 to set or select programs that operate the valve structure 442 anddirect air or other fluid toward or away from the several chambers ofthe inflatable chamber member 416. The valve structure 442 is a anassembly of one or more solenoid valves which are operated or activatedby electrical signals supplied by the microprocessor incorporated intothe board 444. The control structure 438 may contain suitable vents andeven a suitable fan (not shown) to remove heat from within the controlstructure 438. A suitable power supply will also be positioned withinthe control structure 438 to receive 115 Volt power readily available ata wall plug to the desired power level to operate the solenoid valves442, the fan if used, and the microprocessor board 444.

The present invention may be embodied in other specific forms withoutdeparting from its spirit or essential characteristics. The describedembodiments are to be considered in all respects only as illustrativeand not restrictive. The scope of the invention is, therefore, indicatedby the appended claims rather than by the foregoing description. Allchanges which come within the meaning and range of equivalency of theclaims are to be embraced within their scope.

1. An inflatable mattress system comprising: a plurality of inflatablechambers assembled to define a support surface to support an occupanthaving at least one limb, each of said inflatable chambers having atleast one wall member forming an interior volume, said wall member beingmade from a flexible material selected to retain fluid, each of saidplurality of inflatable chambers having a chamber connector for fluidcommunication with said interior volume, said at least one wall memberbeing deflectable between a first inflated position and a secondinflated position different from said first inflated position; aplurality of deflectable resistors each of which predictably varies itselectrical resistance upon deflection from a first configuration to asecond configuration, each of said plurality of deflectable resistorsbeing attached to said at least one wall member of an inflatable chamberof said plurality of inflatable chambers to deflect between said firstconfiguration and said second configuration upon movement of said atleast one wall member between said first inflated position and saidsecond inflated position to generate a deflection signal uponapplication of electrical power to said deflectable resistors reflectiveof said inflatable chamber movement; an inflatable limb elevationchamber configured for positioning on said support surface to support alimb of said occupant, said inflatable limb elevation chamber includingat least one elevation chamber wall member having an elevation chamberinterior volume, said elevation chamber wall member being made from aflexible material selected to retain fluid, said at least one elevationchamber wall member being deflectable between a first inflated elevationchamber position and a second inflated elevation chamber positiondifferent from said first inflated elevation chamber position, saidelevation chamber having an elevation chamber connector for fluidcommunication with said elevation chamber interior volume; a fluidsource for supplying a fluid under pressure into each interior volume ofsaid plurality of inflatable chambers and into said elevation chamberinterior volume; a first conduit means connected to each of said chamberconnectors and said elevation chamber connector for communicating fluidto and from said interior volume and said elevation chamber interiorvolume; a second conduit means connected to said fluid source forcommunicating fluid to and from said fluid source; a discharge means forcommunicating fluid away from said interior volume and said elevationchamber interior volume; a valve connected to said first conduit means,said second conduit means and said discharge means, said valve beingoperable among a first position in which said valve places said firstconduit means in communication with said second conduit means forsupplying fluid from said fluid source to said interior volume and saidelevation chamber interior volume, a second position in which said valveplaces said first conduit means in fluid communication with saiddischarge means, and a third position in which said first conduit meansis inhibited from communicating fluid to and from said interior volumeand said elevation chamber interior volume; and a controller connectedto each of said plurality of deflectable resistors for supplying anelectrical signal thereto and for receiving said deflection signaltherefrom, said controller being configured to generate operatingcommands for operating said valve among said first position, said secondposition and said third position, said controller being connected tosaid valve to supply said operating commands to said valve.
 2. The limbelevation chamber of claim 1, wherein said elevation chamber isremovable from said support surface.
 3. The inflatable mattress of claim1, wherein said controller includes a processor having a set ofinstructions for receiving said deflection signals and deriving anamount of said inflatable chamber movement and directing said controllerto deliver said operating commands for placing said valve in said firstposition, said second position, and said third position.
 4. Theinflatable mattress of claim 3, wherein said controller furthercomprises a valve controller, communicatively coupled to said processorand said valve, said valve controller configured to receive an operatingcommand to select at least one of said plurality of inflatable chambersand said elevation chamber in response to a command from said processor.5. The inflatable mattress of claim 4, wherein said controller furthercomprises a reading device, communicatively coupled to said processorand said plurality of deflectable resistors, said reading deviceconfigured for receiving said deflection signal and transmitting saiddeflection signal to said processor.
 6. The inflatable mattress of claim5, wherein said controller further comprises a fluid controller,communicatively coupled to said processor and said fluid source, saidfluid controller configured for actuating said fluid source in responseto an operating command from said processor.
 7. The inflatable mattressof claim 1, in which said inflatable limb elevation chamber has at leastone elevation chamber deflectable resistor that predictably varies itselectrical resistance upon deflection from a first elevation chamberconfiguration to a second elevation chamber configuration when anelectrical signal is applied thereto, said elevation chamber deflectableresistor being attached to said at least one elevation chamber wallmember of said elevation chamber to deflect therewith upon movement ofsaid at least one elevation chamber wall member between said firstinflated elevation chamber position and said second inflated elevationchamber position for generating an elevation chamber deflection signalreflective of said elevation chamber movement, said elevation chamberdeflectable resistor connected to said controller for supplying anelectrical signal thereto and for receiving said elevation chamberdeflection signal therefrom.
 8. An inflatable mattress systemcomprising: a plurality of inflatable chambers assembled to define asupport surface having a width and a central axis, said support surfacebeing sized to support an occupant having at least one limb, each ofsaid inflatable chambers having at least one wall member forming aninterior volume, said wall member being made from a flexible materialselected to retain fluid, each of said plurality of inflatable chambershaving a chamber connector for fluid communication with said interiorvolume, said at least one wall member being deflectable between a firstinflated position and a second inflated position different from saidfirst inflated position; a plurality of deflectable resistors each ofwhich predictably varies its electrical resistance upon deflection froma first configuration to a second configuration, each of said pluralityof deflectable resistors being attached to said at least one wall memberof an inflatable chamber of said plurality of inflatable chambers todeflect from said first configuration to said second configuration uponmovement of said at least one wall member between said first positionand said second position to generate a deflection signal reflective ofsaid inflatable chamber movement upon application of electrical power tosaid deflectable resistors; an inflatable limb elevation chamberconfigured for positioning on said support surface to support a limb ofsaid occupant, said elevation chamber including at least one elevationchamber wall member forming an elevation chamber interior volume, saidelevation chamber wall member being made from a flexible materialselected to retain fluid, said at least one elevation chamber wallmember being deflectable between a first inflated elevation chamberposition and a second inflated elevation chamber position different fromsaid first inflated elevation chamber position, said elevation chamberhaving an elevation chamber connector for fluid communication with saidelevation chamber interior volume, and said elevation chamber beingsized to extend substantially normal to said central axis forpositioning proximate the feet of the occupant; a fluid source forsupplying a fluid under pressure into each interior volume of saidplurality of inflatable chambers and into said elevation chamberinterior volume; a first conduit means connected to said chamberconnector and said elevation chamber connector for communicating fluidto and from said interior volume and said elevation chamber interiorvolume; a second conduit means connected to said fluid source forcommunicating fluid to and from said fluid source; a discharge means forcommunicating fluid away from said interior volume and said elevationchamber interior volume; a valve connected to said first conduit means,said second conduit means and said discharge means, said valve beingoperable among a first position in which said valve places said firstconduit means in communication with said second conduit means forsupplying fluid from said fluid source to said interior volume and saidelevation chamber interior volume, a second position in which said valveplaces said first conduit means in fluid communication with saiddischarge means; and a controller connected to each of said pluralitydeflectable resistors for supplying an electrical signal thereto and forreceiving said deflection signal therefrom, said controller beingconfigured to generate operating commands for operating said valvebetween said first position and said second position said controllerbeing connected to said valve to supply said operating commands to saidvalve.
 9. The inflatable mattress system of claim 8 wherein said limbelevation chamber has a support surface that is arcuate.
 10. Theinflatable mattress system of claim 8 wherein said limb elevationchamber has means for securing said elevation chamber to said supportsurface.
 11. The inflatable mattress system of claim 10 wherein saidmeans for securing is a member on hook and pile fastener
 12. Theinflatable mattress system of claim 8 wherein said limb elevationchamber has multiple compartments.
 13. The inflatable mattress system ofclaim 8 wherein said limb elevation chamber extends substantially thewidth of said support surface.
 14. An inflatable limb elevation chamberconfigured for positioning on a support surface to support a limb of animmobile person on said support surface, said support surface having awidth and an axis, said inflatable elevation chamber comprising: anelevation chamber wall member forming an elevation chamber interiorvolume, said elevation chamber wall member being made from a flexiblematerial selected to retain fluid, said at least one elevation chamberwall member being deflectable between a first inflated elevation chamberposition and a second inflated elevation chamber position different fromsaid first inflated elevation chamber position said elevation chamberbeing sized to extend substantially normal to said central axis forpositioning under the limb of the immobile person thereon; an elevationchamber connector positioned in a chamber wall for fluid communicationwith said elevation chamber interior volume and connectable to a sourceof fluid and a vent to vent fluid from said elevation chamber.
 15. Theinflatable limb elevation chamber of claim 14 wherein said elevationchamber interior volume has multiple interior chambers with an elevationchamber connector positioned for fluid communication with each of saidmultiple interior chambers.
 16. The inflatable limb elevation chamber ofclaim 14 wherein said elevation chamber wall member has a deflectableresistor positioned thereon which predictably varies its electricalresistance upon deflection of said elevation chamber wall member from afirst configuration to a second configuration to generate a deflectionsignal reflective of said deflection upon application of electricalpower to said deflectable resistor.
 17. The inflatable limb elevationchamber of claim 14 wherein said inflatable limb elevation chamber hasopposite ends with said elevation chamber wall attached thereto andextending therebetween.
 18. The inflatable limb elevation chamber ofclaim 17 further including a strap extending from each of said oppositeends.
 19. The inflatable limb elevation chamber of claim 18 furtherincluding securing means attached to each of said straps to secure saidinflatable limb elevation chamber to said support surface.
 20. Theinflatable limb elevation chamber of claim 18 wherein each of saidstraps is sized to extend from its respective opposite end under saidsupport surface.
 21. The inflatable limb elevation chamber of claim 19wherein said securing means includes one of hook or pile member of ahook and pile fastener affixed to each of said straps and the other ofsaid hook or pile member affixed to said support surface.